Embodiments of the invention are developed from Chinese patent application No. of 200410002605.0 and title of “L, R, C method and device for casting amorphous, ultra-microcrystalline, microcrystalline and the like metal profiles” (hereinafter referred to as patent L, the following specification of patent L refers to the specification of the invention with publication No. of CN101081429B), and it's the further improvement of patent L which is hereby incorporated by reference. The embodiments of the present invention are more mature and advanced, with simpler equipment, cheaper cost and better product performance compared to patent L.
The first “R”—represents room temperature. “R” is the first capital letter of room temperature.
The second “R”—represents rapid solidification. “R” is the first capital letter of rapid solidification.
“C”—represents continuous casting. “C” is the first capital letter of continuous casting.
The operating parameters of the embodiments of the present invention and the patent L are both with a temperature of t=−190° C., a pressure of p=1.877 bar, a thickness of liquid nitrogen spray h=2 mm, a maximum liquid nitrogen ejection speed of kmax=30 m/s. The operating parameters of working chamber of patent L is at a constant temperature of tb=−190° C. and at a constant pressure of pb=1 bar. The temperatures “t” of liquid nitrogen ejected and “tb” of working chamber are both −190° C. in order to avoid the heat exchange among air in working chamber, equipment and liquid nitrogen ejected because all the temperatures of them are −190° C. when liquid nitrogen ejected to small length metal slab Δm of solidified and cool casted amorphous, ultra-microcrystalline, microcrystalline pulled from the outlet of hot casting mold, and the ejected liquid nitrogen comes into contact with the small length metal slab at cross section (the cross section C shown in FIG. 4). In the time interval Δτ corresponding to the different rapid solidification and cooling rate Vk in getting amorphous, ultra-microcrystalline, microcrystalline, the heat exchange only occurs between the ejected liquid nitrogen and the heat conducted from the liquid metal end of small length metal slab Δm to the cross section (the cross section C shown in FIG. 4) of ejected liquid nitrogen and Δm, wherein the heat contains total internal heat of small length metal slab Δm from initial rapid solidification and cooling temperature t1 to ending cooling temperature t2=−190° C. The ejected liquid nitrogen absorbs the heat quickly and completely and gasifies to low temperature nitrogen with a temperature of t=−190° C., a pressure of p=1.877 bar through endothermic gasification phase transition, meanwhile the liquid metal of small length metal slab Δm is solidified rapidly and cool casted to amorphous, ultra-microcrystalline, microcrystalline small length metal slab Δm at an ending cooling temperature of t2=−190° C. Thus the cooling capacity of ejected liquid nitrogen is only used to rapidly solidify and continuously cast amorphous, ultra-microcrystalline, microcrystalline metal profiles without any loss. It ensures the amorphous, ultra-microcrystalline, microcrystalline metal profiles at a temperature of t2=−190° C. can be casted continuously by patent L. But a huge working chamber with a constant temperature tb=−190° C. and constant pressure pb=1 bar is needed. To build a huge working chamber, a low-temperature refrigerator with high-power is needed to keep the temperature of air in working chamber and temperature of device at tb=−190° C. Meanwhile, vacuum and insulation technology are adopted to keep temperature of air in working chamber and temperature of device at tb=−190° C. and constant pressure pb=1 bar. It makes the implementation of patent L carry disadvantages of high cost and great technical difficulty.
But, does the temperature of air in working chamber and temperature of device really need to be at a constant low temperature of tb=−190° C.? How much space is needed in the working chamber? Can the temperature of room air, higher or lower than the temperature of room air be adapted to the temperature of working chamber? The process of endothermic gasification phase transition of small length metal slab Δm pulled from the outlet of hot casting mold and the ejected liquid nitrogen at the cross section C has heretofore not been adequately addressed.